/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.db.mpp.execution.operator.schema;

import org.apache.iotdb.commons.exception.MetadataException;
import org.apache.iotdb.commons.path.PartialPath;
import org.apache.iotdb.db.metadata.template.Template;
import org.apache.iotdb.db.mpp.common.header.ColumnHeader;
import org.apache.iotdb.db.mpp.common.header.ColumnHeaderConstant;
import org.apache.iotdb.db.mpp.execution.driver.SchemaDriverContext;
import org.apache.iotdb.db.mpp.execution.operator.OperatorContext;
import org.apache.iotdb.db.mpp.execution.operator.source.SourceOperator;
import org.apache.iotdb.db.mpp.plan.planner.plan.node.PlanNodeId;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.read.common.block.TsBlock;
import org.apache.iotdb.tsfile.read.common.block.TsBlockBuilder;

import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

public class TimeSeriesCountOperator implements SourceOperator {
    private final PlanNodeId sourceId;
    private final OperatorContext operatorContext;
    private final PartialPath partialPath;
    private final boolean isPrefixPath;
    private final String key;
    private final String value;
    private final boolean isContains;
    private final Map<Integer, Template> templateMap;

    private boolean isFinished;

    private final List<TSDataType> outputDataTypes;

    @Override
    public PlanNodeId getSourceId() {
        return sourceId;
    }

    public TimeSeriesCountOperator(
            PlanNodeId sourceId,
            OperatorContext operatorContext,
            PartialPath partialPath,
            boolean isPrefixPath,
            String key,
            String value,
            boolean isContains,
            Map<Integer, Template> templateMap) {
        this.sourceId = sourceId;
        this.operatorContext = operatorContext;
        this.partialPath = partialPath;
        this.isPrefixPath = isPrefixPath;
        this.key = key;
        this.value = value;
        this.isContains = isContains;
        this.templateMap = templateMap;
        this.outputDataTypes =
                ColumnHeaderConstant.countTimeSeriesColumnHeaders.stream()
                        .map(ColumnHeader::getColumnType)
                        .collect(Collectors.toList());
    }

    @Override
    public OperatorContext getOperatorContext() {
        return operatorContext;
    }

    @Override
    public TsBlock next() {
        isFinished = true;
        TsBlockBuilder tsBlockBuilder = new TsBlockBuilder(outputDataTypes);
        long count = 0;
        try {
            if (key != null && value != null) {
                count =
                        ((SchemaDriverContext) operatorContext.getInstanceContext().getDriverContext())
                                .getSchemaRegion()
                                .getAllTimeseriesCount(partialPath, isPrefixPath, key, value, isContains);
            } else {
                count =
                        ((SchemaDriverContext) operatorContext.getInstanceContext().getDriverContext())
                                .getSchemaRegion()
                                .getAllTimeseriesCount(partialPath, templateMap, isPrefixPath);
            }
        } catch (MetadataException e) {
            throw new RuntimeException(e.getMessage(), e);
        }
        tsBlockBuilder.getTimeColumnBuilder().writeLong(0L);
        tsBlockBuilder.getColumnBuilder(0).writeLong(count);
        tsBlockBuilder.declarePosition();
        return tsBlockBuilder.build();
    }

    @Override
    public boolean hasNext() {
        return !isFinished;
    }

    @Override
    public boolean isFinished() {
        return isFinished;
    }

    @Override
    public long calculateMaxPeekMemory() {
        // the integer used for count
        return 4L;
    }

    @Override
    public long calculateMaxReturnSize() {
        // the integer used for count
        return 4L;
    }

    @Override
    public long calculateRetainedSizeAfterCallingNext() {
        return 0L;
    }
}
